1. Sustainable Sciences Institute, Managua, Nicaragua;
2. Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, California;
3. Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California;
4. Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan;
5. Centro de Salud Sócrates Flores Vivas, Ministry of Health, Managua, Nicaragua